Dental syringe.



M. PAYNE.

DENTAL SYRINGE.

APPLICATION men APR. 12. 1915.

Patnted Aug. 24, 1915.

llllllllllvll 4' "I'll MATTHEW PAYNE, 0F YONKERS, NEW YORK.

DENTAL SYRINGE.

Specification of Letters Patent.

Application filed April 17, 1915. Serial No. 22,149.

To all whom it may concern Be it known that I, MATTHEW PAYNE, a citizen of the United States, residing at Yonkers, in the county of l/Vestchester and State of New York, have invented certain new and useful Improvements in Dental Syringes, of which thefollowing is a full, clear, and exact specification.

This invention relates to hypodermic syringes for use by dentists, surgeons, and other practitioners.

The syringe includes a barrel, to the outlet of which a hypodermic needle is connected, and a piston movable in the barrel and adapted to eject fluid through the needle. As heretofore made, the piston has been fitted loosely in the barrel so that it is necessary to pack the outlet end of said barrel, and it has been necessary to remove the piston in order to fill the barrel at the end whereby the packing was placed.

One object of the present invention is to dispense with all packing and another object is to provide means for retaining the piston in the cylinder, thereby avoiding unsanitary conditions which might result from the drugs employed attacking the packing materiahand preventing the piston from becoming separated from the barrel and mislaid or lost. Inasmuch as the piston is not removable for filling, means are provided for filling the barrel at the side and for preventing the contents of the barrel from being discharged through the lateralfilling opening when the piston is advanced for forcing the fluid through the needle.

A further object is to provide an improved form of connection between the needle and barrel, whereby the use of a wrench will not be necessary, as heretofore, fol attaching and detaching the needle. At the same time, provision is made for using the standard or stock needle with the improved form of barrel, so that in case the preferred form of needle is not obtainable, the device may be used with a stock needle.

The invention will be first hereinafter described in connection with the accompanying drawings, which constitute a part of this specification, and then more specifically defined in the claims at the end of the description.

In the accompanying drawings, wherein similar reference characters are used to designate corresponding parts throughout the several views: Figure 1 is a side view of a syringe .made substantially in accordance w th the present invention. Fig. 2 is a longltudinal sectional view, the needle and plunger being shown in elevation. Fig. 3 is across section through the filling opening with the valve sleeve in open position. Fig.

Patented Aug. 24, 1915.

4 is a similar view showing the valve sleeve in closed position. Fig. 5 is a broken detailed view of part of the barrel and the valve sleeve, showing the means for limiting the rotatlon of said valve sleeve. Fig. 6'is an enlarged detailed view of the preferred form of needle with' the reducing collar. Fig. 7 is a detailed view of a stock needle and the nipple used therewith for connecting said needle to the barrel of my improved syringe, and Fig. 8 is a broken longitudinal section of the outlet end of the barrel with the nipple and stock needle attached thereto.

The barrel 1 has a smooth bore 2 in which is closely fitted the head 3 of the piston 4, the latter being provided with a suitable handle 5 on its outer end. The stem portion 4 of the piston is of reduced size compared with the piston head 3, thereby forming a shoulder 6 which is adapted to contact with the end portion 7 of the collar 8 which is screwed on to the outer end of the barrel. The piston is thus retained in the barrel, so that it, cannot become separated and lost without the removal of the collars 8. Because of the fact that the piston head 3 closely fits the bore of the cylinder, no packing is required at .the outer end of the barrel.

The usual rest 9 for two fingers of the hand which manipulates this syringe, is in this instance rigidly secured upon the barrel in any suitable way and is provided with a groove 10 in its outer face surrounding the barrel. Between the rest 9 and the collar 8, a sleeve 11 is fitted to turn upon the barrel. The outer end of this sleeve fits in a groove 12 in the inner end of the collar 8, while the inner end of said sleeve fits into the groove 10' in the rest 9. The sleeve is provided with a funnel-shaped filling opening 13 adapted to register with a radial opening 14 in the barrel. A portion of the inner edge of the sleeve is cutaway, as at 15 in Fig. 5, and a stop pin 16, Figs. 2 and 5, is placed in the groove 10 to coiiperate with said out out portion 15 for limiting the rotary movement of the sleeve on the barrel.

communication with the opening 14. In the latter position, the sleeve acts as a valve for closing the opening 14 in the barrel and :preventing the escape of the fluid from said opening after the barrel has been filled and the piston is started inward.

It will be noted that the collar 8 serves the double function of retaining the piston in the barrel and holding the valve sleeve 11 in proper position, both of these objects being fulfilled when the collar is fully screwed onto the barrel. Said collar is provlded with a milled surface 17 whereby it may be manipulated by hand and without requiring the use of a wrench. It will also be observed that the length of the barrel beyond the filling opening 14 is ample to permit the piston head 3 to be moved to a position beyond said opening when the barrel is to be filled.

The inner or forward end of the barrel is screw threaded externally to receive a collar or coupling member 18. The bore of the barrel is flared at its inner end to provide a close fit for a reducing collar 19 which is conical in form and fits around the correspondingly shaped innerend 20 of my improved needle 21. Beyond the conical inner end 20, a bead or projecting flange 22 is formed around the needle. flange forms a stop for the reducing collar 19 on one side and at the other side provides an abutment for the reduced extremity 23 of the collar 18. The needle will, therefore, be tightly clamped in the metal or other washer 19, and said washer firmly seated in the flared outer end portion of the bore in the barrel, when the collar 18 is screwed down tight onto the barrel. The collar 18 is provided with a milled surface 24 so that it may be easily manipulated by hand, rendering it unnecessary to employ a wrench.

The stock needle at the present time, that is, the form of needle now generally in use, has an internally threaded inner end with a -wrench surface 25 around it, as illustrated in Fig. 7. In order to provide for the use of such a needle with my improved form of syringe, I employ a connecting piece or nipple 26, Fig. 7, which has its inner end 27 formed to fit the flared end of the bore in the barrel, is also provided with a shoulder This bead or 23 of the collar 18, and has its outer end a threaded, as at 29, to fit the internal threads in the stock needle. As illustrated in Fig. 8, the nipple 26 may, therefore, be clamped by the collar 18 in the flared end of the bore of the barrel, and the stock'needle 30 may then be attached to the threaded end 29 of the needle in the same manner as in the old form of syringe shown in Patent No. 1044688.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a syringe, the combination with a barrel having a filling opening in its side, and a circumferential projection in advance of said opening provided with a groove, of

a iston in the barrel having a shoulder, a va ve sleeve rotatably mounted around the part of the barrel containing the opening and having an opening movable into and out of register with the opening in the barrel, and a collar on the end of the barrel having a reduced portion to engage the shoulder on the piston for preventing the entire with-- drawal of said piston, the collar also having a groove fitting over one end of the valve sleeve, the other end of the valve sleeve fittlng in the groove in the circumferential projection on the barrel. 7

2. In a syringe, the combination with a barrel having a filling opening in its side, of a piston fitted in said barrel and having a shoulder, a valve sleeve rotatably mounted around the part of the barrel contalning said opening and having an opening movable into and out of register with the opening in the barrel, and a collar on the end of the barrel for holding the valve sleeve in position and preventing the entire withdrawal of the piston by coming in contact with the shoulder thereon.

3. In a syringe, the combination with a barrel having a filling opening in its side and a circumferential projection provided with a groove, of a valve sleeve rotatably mounted around the part of the barrel containing said opening and having-an opening movable into and out of register with the opening in the barrel, one end of said sleeve being arranged in said groove and being partially cut away, and a stop in the groove cooperating with said cut away portion to limit the rotation of the sleeve.

In testimony whereof I have signed my name to this specification.

MATTHEW PAYNE. 

